HERPES

Question 1

1. what type specific to equine?
2. where affected?
3. EHV-1 causes what most commonly?

EHV-4?

Answer 1

1. type 4
2. resp, eye, oral cavity, genitalia
3. abortion, neurologic dz, +/- resp

resp (abortion)

Question 2

(rhinopneumonitis)

1. spread how?
2. Cx?

Answer 2

1. direct contact, aerosol, fomites
2. mostly upper resp (young more affected), like a mild flu, nasal discharge (seromucoid),

rarely bronchopneumonia, keratitis, conjuctivitis

Question 3

(Herpes Abortion)

1. almost always due to what type?
2. when does it occur?
3. signs in mare?
4. aborted fetus looks like?

Answer 3

1. EHV-1
2. last 4 mo of pregnancy
3. usually none
4. fresh rather than autolyzed (like with EVA)

(high levels in fetal fluid and placenta)

(foal may be born alive but will be very weak w/ lower resp signs and extensive tissue dmg to internal organs)

Question 4

(Equine Herpes Myeloencephalopathy)

1. what causes?
2. viremia?
3. fever or CNS signs first?
4. what are signs of neuro dz?

Answer 4

1. any strain of EHV-1
2. in neurologic, not in abortion
3. fever (rarely still there when CNS problems begin)
4. incoordination, bladder paresis, reduced tail tone

Question 5

(neuro dz)

1. more signs from spinal cord or brain damage?

from what?

2. what is a bad prognostic sign?
3. how quickly do they improve?

Answer 5

1. spinal cord

vasculitis and ischemia

2. rapid progression to recumbency
3. very gradually (months)

Question 6

1. what makes dx herpes challening?

Answer 6

1. latent infection (lymphoid, nervous tissue)
2. subclinical infections
3. virus infects in spite of high titers
4. many other diseases cause similar signs

Question 7

(Diagnosis of herpres)

1. clinical signs
2. best choices?
3. when to report?
4. how high an increase in titers for serology?

Answer 7

2. virus isolation and rtPCR

(nasal swabs, lymphoid, CNS, fetus, placenta)

< 10 days after infection

3. ANY HERPES + NEURO SIGNS
4. 1:4 over 7-21 days

Question 8

(more diagnosis of herpes)

(CSF)

1. may show what?

2-3. couple more options?

Answer 8

1. xanthochromia, RBCs, elevated protein from inflam blood vessels, +/- ^ WBC
2. IHC
3. histo for characteristic lesions (vasculitis, intranuclear lesions)

Question 9

(treatment)

1. what?

Answer 9

1. symptomatic

NSAIDS, DMSO, corticosteroids is severe (for neurologic complications - vasculitis)

antivirals (give better prog) - acyclovir IV

Question 10

(control)

1. what is most important form of transmission?
2. how far should isolates be?
3. are placenta, fetus, foal infective?
4. via fomites, organic material?
5. when can aborting mare be bred again?

Answer 10

1. viral shedding in resp form
2. 35 feet
3. highly
4. yep
5. not until 2nd cycle

Question 11

(control)

1. how long does natural immunity last?
2. what is an immunomodulator that helps?

how does it help?

3. is vaccination helpful?
4. how long should you quarantine?

Answer 11

1. 3-6 mo (repeat abortion/neuro unlikely though)
2. Zylexis

reduces resp signs

3. controversial - may make Cx worse
4. 4 weeks, 2 weeks if 2-4 neg PCR

Question 12

(prevention)

1. what is the current recommendation for vx? (in regards to neuro form)

Answer 12

1. maintain good herd vaccination protocol and not necessarily vx in the face of an outbreak